A kinetic study of blinking responses in cats

Abstract

Reflexively evoked and eye‐related eyelid responses were recorded using the search coil in a magnetic field technique in alert cats. The downward phase of a blink was a large (up to 21 deg), fast (up to 2000 deg s−1) eyelid displacement in the closing direction, with an almost fixed rise time duration (15‐20 ms); its maximum velocity was achieved in ≈10 ms. Upward eyelid motion was separated into two phases. The first phase consisted of a fast eyelid displacement, with a short duration (≈30 ms) and a maximum velocity up to 900 deg s−1. The second phase had an exponential‐like form, lasting for 200–400 ms, and a maximum velocity ranging between 30 and 250 deg s−1. Maximum blink velocity in the downward direction was linearly related to maximum velocity of the first upward phase. The first phase in the upward direction was never observed if the eyelid stayed closed for a long period (> 50 ms) or moved slowly in the closing direction before it started to open. In these two cases, the upswing motion of the blink reflex contained only the exponential‐like movement characteristic of the second upward phase, and maximum velocity in the downward direction was not related to that of the eyelid upward displacement. Mean duration of eyelid downward saccades was ≈130 ms, and their peak velocities ranged between 50 and 440 ms. A physiological model is presented explaining the active and passive forces involved in both reflex and saccadic eyelid responses. A second‐order system seems to be appropriate to describe the postulated biomechanical model.

Associative and non-associative blinking in classically conditioned adult rats

“…Further study is warranted to more precisely define the kinetics of each type of blink in the rat, as well as the underlying neural circuitry [cf. 41]. …”

Recruitment in Retractor Bulbi Muscle During Eyeblink Conditioning: EMG Analysis and Common-Drive Model

“…Although the firing rate properties of eyeblink neurons resemble those of ocular motoneurons to some extent ( Trigo et al 2003 ), recruitment seems rather different in the two systems. The behavior of ocular motoneurons appears not to result from a common-drive mechanism, but rather from differences in synaptic drives to different motoneurons ( Dean 1997 ; Hazel et al 2002 ).…”

Conditioned Eyelid Movement Is not a Blink

“…For reflex, voluntary, and spontaneous blinks, there is a consistent linear relationship between blink amplitude and maximum velocity analogous to saccadic eye movements Guitton et al 1991;Korosec et al 2006;Sun et al 1997;Trigo et al 2003;VanderWerf et al 2003). The eyelid movements with saccadic vertical gaze shifts, however, are kinematically different from blinks (Fig.…”